Elastic wave device manufacturing method and elastic wave device

ABSTRACT

Functional element units and a connection line electrically connecting the functional element units are formed on one principal surface of a piezoelectric motherboard. A resin support layer enclosing the functional element units is formed on the one principal surface of the motherboard. An elastic wave device with the functional units is obtained by dividing a multilayer body including the motherboard, the functional element units, and the support layer into a plurality of sections along a dicing line. The connection line includes a line main body positioned on the dicing line, and a connection unit in which the line main body and the functional element units are electrically connected. Prior to dividing the multilayer body, a retaining member made of resin which straddles the line main body in the width direction of the line main body is formed separate from the support layer on the motherboard.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to methods for manufacturing elastic wavedevices, and elastic wave devices.

2. Description of the Related Art

As a method for manufacturing an elastic wave device, a method asfollows has been widely known. That is, in this known method, aplurality of element units are formed on a motherboard which is made ofa piezoelectric body, subsequently the motherboard and element units aredivided into sections corresponding to each individual element unit, andthus a plurality of elastic wave devices are manufactured in the samemanufacturing process. An example of such method is disclosed inInternational Publication No. WO2012/132147, for example.

In the manufacturing method disclosed in International Publication No.WO2012/132147, a plurality of element units are first formed on amotherboard which is made of a piezoelectric body. In the formation ofthe element units, a feed line connected to the element units is formedalong with the element units. Next, a support layer having projectionportions is formed on the motherboard so as to enclose the elementunits. Subsequently, a cover member is disposed on the support layer.Thereafter, by dividing a thus obtained multilayer body using a dicingtool into sections corresponding to each individual element unit, aplurality of elastic wave devices are manufactured in the samemanufacturing process.

As disclosed in International Publication No. WO2012/132147, byproviding projection portions on the support layer so as to suppressstrain in the frame-like support layer caused by hardening shrinkage,leak defects in the sealing space can be suppressed.

However, with the method for manufacturing an elastic wave devicedisclosed in International Publication No. WO2012/132147, such a problemoccurs in some case that the feed line is separated from the motherboarddue to a cutting force of dicing, whereby the feed line cannot beremoved. Because of the separation of the feed line electricallyconnected to the functional elements, there arises a problem that anelastic wave device having a short circuit defect is likely to bemanufactured. Further, with the method for manufacturing an elastic wavedevice disclosed in International Publication No. WO2012/132147, in thecase where the number of the projection portions is increased in orderto prevent the separation of the feed line, there arises a problem thatleak defects are likely to be generated because the projection portionsdeformed due to the cutting force of dicing consequently deform asupport member main body.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide a method formanufacturing an elastic wave device that significantly reduces,minimizes or prevents generation of short circuit defects and leakdefects.

In a method for manufacturing an elastic wave device according to apreferred embodiment of the present invention, a plurality of functionalelement units and a connection line that electrically connects theplurality of functional element units are formed on one principalsurface of a motherboard having piezoelectricity. A support layer madeof resin configured to enclose the functional element units is formed onthe one principal surface of the motherboard. An elastic wave deviceincluding the functional element unit is obtained by dividing amultilayer body including the motherboard, the functional element units,and the support layer into a plurality of sections along a dicing line.The connection line includes a line main body positioned on the dicingline, and a connection unit in which the line main body and thefunctional element units are electrically connected. Prior to dividingthe multilayer body, a retaining member made of resin which straddlesthe line main body in the width direction of the line main body isformed separate from the support layer on the motherboard.

In a specific aspect of a method for manufacturing an elastic wavedevice according to various preferred embodiments of the presentinvention, there is provided the retaining member configured to cover anend portion of the connection unit on a line main body side.

In another specific aspect of a method for manufacturing an elastic wavedevice according to various preferred embodiments of the presentinvention, the retaining member is configured so that an area where theretaining member is not provided is larger than an area where theretaining member is provided in a region in which the dicing line ispositioned.

In still another aspect of a method for manufacturing an elastic wavedevice according to various preferred embodiments of the presentinvention, the retaining member and the support layer are formed in thesame technical process or manufacturing step.

An elastic wave device according to another preferred embodiment of thepresent invention includes a piezoelectric substrate, a functionalelement unit, an electrode unit, a support layer, and a cover. Thefunctional element unit is provided on one principal surface of thepiezoelectric substrate. The electrode unit is electrically connected tothe functional element unit. The electrode unit extends to an end sideof the piezoelectric substrate. The support layer is provided on the oneprincipal surface of the piezoelectric substrate so as to enclose thefunctional element unit. The cover is supported by the support layer.The cover covers the functional element unit. The support layer isprovided separate from the end side of the piezoelectric substrate andencloses the functional element unit. The elastic wave device accordingto a preferred embodiment of the present invention further includes aretaining member made of resin. The retaining member is providedseparate from the support layer on the piezoelectric substrate. Theretaining member extends to the end side of the piezoelectric substrate.

According to various preferred embodiments of the present invention, itis possible to provide a method for manufacturing an elastic wave devicecapable of significantly reducing, minimizing or preventing thegeneration of short circuit defects and leak defects.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view for explaining a manufacturing processof an elastic wave device according to a first preferred embodiment ofthe present invention.

FIG. 2 is a schematic plan view for explaining a manufacturing processof an elastic wave device according to the first preferred embodiment ofthe present invention.

FIG. 3 is a schematic plan view for explaining a manufacturing processof an elastic wave device according to the first preferred embodiment ofthe present invention.

FIG. 4 is a schematic cross-sectional view taken along a IV-IV line inFIG. 3.

FIG. 5 is a schematic cross-sectional view taken along a V-V line inFIG. 3.

FIG. 6 is a schematic cross-sectional view illustrating a multilayerbody manufactured in the first preferred embodiment of the presentinvention.

FIG. 7 is a schematic plan view illustrating a multilayer bodymanufactured in the first preferred embodiment of the present invention.

FIG. 8 is a schematic plan view illustrating an elastic wave devicemanufactured in the first preferred embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view taken along a IX-IX line inFIG. 8.

FIG. 10 is a schematic plan view for explaining a manufacturing processof an elastic wave device according to a second preferred embodiment ofthe present invention.

FIG. 11 is a schematic cross-sectional view taken along a XI-XI line inFIG. 10.

FIG. 12 is a schematic plan view illustrating an elastic wave devicemanufactured in the second preferred embodiment of the presentinvention.

FIG. 13 is a schematic cross-sectional view taken along a XIII-XIII linein FIG. 12.

FIG. 14 is a schematic plan view in which an area in the vicinity of anelectrode land in FIG. 12 is enlarged and illustrated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, examples of preferred embodiments of the present inventionwill be described. It is to be noted that the following preferredembodiments are merely examples. The present invention is not intendedto be limited to the following preferred embodiments in any way.

In the drawings referred to in the preferred embodiments and the like,members having functions that are the same or substantially the samewill be referred to as the same reference numerals. Further, thedrawings referred to in the description of preferred embodiments and thelike are schematically depicted. As such, the ratios of dimensions andso on of objects depicted in the drawings may differ from the actualratios of dimensions and so on of those objects. The ratios ofdimensions and so on of the objects may differ from drawing to drawingas well. The specific ratios of dimensions and so on of objects shouldbe understood in consideration of the following descriptions.

First Preferred Embodiment

In a first preferred embodiment of the present invention, a method formanufacturing an elastic wave device 1 illustrated in FIGS. 8 and 9 willbe described referring mainly to FIGS. 1 through 7. In the presentpreferred embodiment, the elastic wave device 1 preferably is a surfaceacoustic wave device, however, it may be another type of elastic wavedevice such as a boundary acoustic wave device or the like, for example.

First, as shown in FIG. 1, a plurality of functional element units 11and a connection line 12 are formed on a motherboard 10. The motherboard 10 is made of, for example, a piezoelectric body. The motherboard10 has piezoelectricity. The motherboard 10 may be configured with apiezoelectric substrate. Further, the motherboard 10 may include apiezoelectric substrate and a non-piezoelectric layer arranged on oneprincipal surface of the piezoelectric substrate. The piezoelectricsubstrate can be configured with, for example, LiTaO₃, LiNbO₃, crystal,or the like. The non-piezoelectric layer can be configured with siliconoxide or the like, for example. A thickness (H₁) of the motherboard 10can be set to about 100 μm to about 300 μm, for example.

The functional element unit 11 and the connection line can be formed by,for example, a sputtering method, a chemical vapor deposition (CVD)method, or the like.

As shown in FIG. 1, the plurality of functional element units 11 areformed in matrix form on the motherboard 10. It is preferable for a rowinterval L₁ between the plurality of functional element units 11 to beabout 500 μm to about 1,800 μm, for example. It is preferable for acolumn interval L₂ between the plurality of functional element units 11to be about 500 μm to about 1,800 μm, for example.

The plurality of functional element units 11 each include at least oneinterdigital transducer (IDT) electrode and excite elastic waves. Forexample, in the case where the elastic wave device 1 is an elastic wavefilter device, the functional element unit 11 may configure at least oneof a ladder-type filter unit and a longitudinally coupled resonator-typeelastic wave filter unit.

The functional element unit 11 includes a plurality of electrode lands13 a through 13 f to which at least one IDT electrode is electricallyconnected. The plurality of electrode lands 13 a through 13 f are eachelectrically connected to the connection line 12.

As shown in FIG. 1 and FIG. 4, the connection line 12 includes a linemain body 12 a and a connection unit 12 b. It is preferable for a columninterval L₃ of the line main body 12 a to be about 500 μm to about 1,800μm, for example. It is preferable for a row interval L₄ of the line mainbody 12 a to be about 500 μm to about 1,800 μm, for example. It ispreferable for a thickness H₂ of the line main body 12 a to be about 0.5μm to about 5 μm, for example. The connection unit 12 b electricallyconnects the line main body 12 a to the functional element unit 11(specifically, the electrode lands 13 a through 13 f of the functionalelement unit 11). To be more specific, the electrode lands 13 a through13 f are each electrically connected to the line main body 12 a via theconnection unit 12 b. It is preferable for line widths W_(L1), W_(L2) ofthe line main body 12 a and a line width W_(L3) of the connection unit12 b to be about 5 μm to about 30 μm, for example.

Next, as shown in FIG. 2, a support layer 20 made of resin is formed onthe motherboard 10 so as to enclose each of the plurality of functionalelement units 11. It is preferable for a thickness H₃ of the supportlayer 20 to be about 5 μm to about 20 μm, for example. The support layer20 can be formed through patterning a resin layer, having been formed onthe overall motherboard 10 by screen printing or the like, using aphotolithographic method or the like, for example. The support layer 20can be configured with, for example, a polyimide resin, an epoxy resin,a silicone resin, or the like.

A retaining member 21 is so formed as to intersect with the line mainbody 12 a. The retaining member 21 is formed on the motherboard 10 so asto straddle the line main body 12 a in the width direction of the linemain body 12 a. It is preferable for a thickness H₄ of the retainingmember 21 to be about 5 μm to about 20 μm, for example. Note that thethickness H₄ of the retaining member 21 may be smaller than thethickness H₃ of the support layer 20 and the member may not be connectedto the cover. It is preferable for widths W_(L4) and W_(L5) of theretaining member 21 to be about 10 μm to about 80 μm, for example. It ispreferable for an interval D₂ of the retaining member 21 to be about 300μm to about 1,700 μm, for example. As such, the retaining member 21includes an intersecting portion 21 a that is not connected to thesupport layer 20 and intersects with the line main body 12 a. Aplurality of intersecting portions 21 a are provided with intervalstherebetween along a direction in which the line main body 12 a extends.A direction in which the intersecting portion 21 a extends and thedirection in which the line main body 12 a extends may be slanted orinclined relative to each other; however, typically speaking, thedirection in which the intersecting portion 21 a extends and thedirection in which the line main body 12 a extends are preferablyperpendicular or substantially perpendicular to each other. Only theintersecting portion 21 a of the retaining member 21 is provided on theline main body 12 a, whereas a portion of the retaining member 21 otherthan the intersecting portion 21 is not provided on the line main body12 a. In other words, a portion of the line main body 12 a other thanthe portion covered by the intersecting portion 21 a is exposed from theretaining member 21. The support layer 20 is not provided on the linemain body 12 a, and covers the electrode lands 13 a through 13 f. Notethat in the first preferred embodiment, an example in which theretaining member 21 and the support member 20 use the same material andare formed simultaneously through patterning using a photolithographicmethod, for example, is described. In other words, an example in whichthe retaining member 21 and the support member 20 are integrally formedis described. It is to be noted that, however, the retaining member 21and the support layer 20 may be formed using different materials throughdifferent forming methods, respectively.

Next, as shown in FIGS. 3 through 5, by providing a plate-shaped cover30 on the support layer 20 so as to cover the plurality of functionalelement units 11, the functional element units 11 are sealed in a spaceconfigured by the motherboard 10, the support layer 20, and the cover30. It is preferable for a thickness H₅ of the cover 30 to be about 10μm to about 60 μm, for example. The cover 30 can be configured with amaterial such as resin, glass, ceramics, or the like, for example. Thesurface shape of the plate-shaped cover includes not only a planarsurface but also a curved surface. The cover 30 is not limited to aconfiguration in which the cover 30 is formed with a single material;the cover 30 may be a multilayer body formed of a plurality of layersmade of different materials.

Next, as shown in FIG. 6, via holes 31 configured to extend to theelectrode lands 13 a through 13 f are formed in the support layer 20 andthe cover 30. Thereafter, a plurality of under-bump metals 32 and bumpelectrodes 33 are sequentially formed on the exposed portions of theelectrode lands 13 a through 13 f, respectively, such that a multilayerbody 35 as shown in FIGS. 6 and 7 is completed. The plurality ofunder-bump metals 32 can be formed simultaneously by plating while theelectrode lands 13 a through 13 f being supplied with electricity viathe connection line 12, for example. As such, the connection line 12 iscalled a feed line in some case in the present invention.

Subsequently, the multilayer body 35 is divided into a plurality ofsections by dicing along a dicing line L whose column interval L₃ androw interval L₄ are so set as to form a lattice pattern same as the linemain body 12 a, as shown in FIG. 7. As a result, the elastic wave device1 shown in FIGS. 8 and 9 is completed. It is preferable for a widthW_(D) of the dicing line L to be about 10 μm to about 50 μm, forexample.

The elastic wave device 1 includes a piezoelectric substrate 40 formedof the motherboard 10 (see FIG. 9). The functional element unit 11 isprovided on the piezoelectric substrate 40. The functional element unit11 includes at least one IDT electrode and the plurality of electrodelands 13 a through 13 f to which at least the one IDT electrode iselectrically connected. An electrode unit 41 (see FIG. 8) configuredwith the connection unit 12 b of the connection line 12 is electricallyconnected to the electrode lands 13 a through 13 f, respectively. Theelectrode unit 41 extends to an end side of the piezoelectric substrate40. The support layer 20 configured to enclose the functional elementunit 11 is provided on the piezoelectric substrate 40. A cover 42supported by the support layer 20 is provided on the piezoelectricsubstrate 40. The cover 42 is defined by the cover 30.

In the present preferred embodiment, the dicing line L is set so thatthe line main body 12 a is positioned on the dicing line L. The widthW_(D) with which the motherboard 10 is cut by a dicing saw is largerthan the widths W_(L1) and W_(L2) of the line main body 12 a. As such,the line main body 12 a is removed by the dicing and the electrode lands13 a through 13 f are electrically insulated from each other.

Incidentally, the dicing saw is likely to be clogged if a material madeof resin is present on the dicing line. In view of this, it ispreferable not to arrange a support layer made of resin on the dicingline.

However, the inventors of preferred embodiments of the present inventionhave discovered through extensive research that leak defects are likelyto be generated, in the case where a projection portion connected to thesupport layer is provided on the dicing line, due to deformation of thesupport layer of the elastic wave device to be manufactured. Theinventors have also discovered that short circuit defects are easilycaused by separation of the connection line during the dicing.

As such, in various preferred embodiments of the present invention, asshown in FIG. 2, the retaining member 21 preferably is formed andconfigured to intersect with the line main body 12 a of the connectionline 12 and not connected to the support layer (typically speaking,formed or configured to be perpendicular or substantially perpendicularto the line main body 12 a). Further, it is preferable for an area wherethe retaining member 21 is not disposed to be larger than an area wherethe retaining member 21 is disposed on the dicing line L. Explanationabout this will be specifically given based on the present preferredembodiment. That is, size of the intersecting portions in a dicingregion, which is a product of the number of intersecting portionstherein and an area calculated by W_(D)×W_(L4), is taken as an areavalue A₁. Meanwhile, size of the dicing region calculated by W_(D)×L₄ istaken as an area value A₂. In this case, in order to make an area of theintersecting portions removed by the dicing larger than an area of aregion exposed on the piezoelectric substrate by the dicing, it ispreferable for the area value A₁ of the intersecting portions to beequal to or less than half the area value A₂ of the dicing region. Assuch, it is preferable for a ratio of A₂/A₁ to be equal to or more than2. Specifically, in a non-limiting working example of D₂: 500 μm, W_(D):10 μm, W_(L4): 80 μm, L₄: 1,000 μm, and the number of intersectingportions: 2, a calculation result of A₂/A₁=3.12 is obtained. Likewise,size of the intersecting portions in a dicing region, which is a productof the number of intersecting portions therein and an area calculated byW_(D)×W_(L3), is taken as an area value A₃. Size of the dicing regioncalculated by W_(D)×L₃ is taken as an area value A₄. In a workingexample of D4: 300 μm, W_(D): 10 μm, W_(L5): 50 μm, L₃: 500 μm, and thenumber of intersecting portions: 2, a calculation result of A₄/A₃=6.25is obtained. It is preferable for A₂/A₁ and A₄/A₃ to be greater than 3.Further, in order to significantly reduce, minimize or preventgeneration of separation of the line main body 12 a, it is preferable todispose a plurality of retaining members 21 at predetermined intervalsin a direction in which the line main body 12 a extends so as to supportthe line main body 12 a at a plurality of supporting portions. However,as the number of portions at which the retaining members 21 are disposedis increased, clogging in the dicing saw increases. Here, in the methodfor manufacturing an elastic wave device disclosed in InternationalPublication No. WO2012/132147, in the case where the widths W_(L4) andW_(L5) of the retaining member 21 are made narrower in the formationthereof than the width of the support layer 20, the retaining member 21becomes likely to be deformed by the cutting force of dicing. As aresult, the support layer is deformed by the retaining member 21connected to the support layer 20 so that an elastic wave device havingleak defects might be manufactured.

However, by forming the retaining member 21 which is not connected tothe support layer 20 and carrying out dicing, leak defects caused by thedeformation of the retaining member are significantly reduced, minimizedor prevented. In addition, the separation of the connection line 12during the dicing is significantly reduced, minimized or prevented, andthe clogging in the dicing saw is significantly reduced, minimized orprevented as well. As a result, generation of an elastic wave devicehaving leak defects and short circuit defects is significantly reduced,minimized or prevented. This makes it possible to manufacture elasticwave devices at a high non-defective product ratio. Further, theretaining member 21 smaller in width than the support layer 20 can beformed, such that a time interval at which a dressing process forremoving the clogging in the dicing saw is carried out is lengthenedbecause the dicing saw is prevented from being clogged. Alternatively,an effect that a time interval for exchanging a dicing saw is lengthenedand an effect that the generation of short circuit defects issignificantly reduced, minimized or prevented is obtained at the sametime. To be more specific, in the case where the working examples in thefirst preferred embodiment and a first comparison example in which theretaining member 21 was not provided in the first preferred embodimentwere compared with regard to a ratio of generation of short circuitdefects using 12,000 samples, the number of generated short circuitdefects in the working examples of the first preferred embodiment was 0,which is 0 ppm, while in the first comparison example, the number ofgenerated short circuit defects was 8, which is 667 ppm. Further, in thecase where the comparison with regard to a ratio of generation of leakdefects in both the examples was carried out, several leak defects weregenerated in the ten thousand samples in the first comparison example,that is, generated at a ratio of 100 ppm to 900 ppm, while in the firstpreferred embodiment, the number of leak defects was 0 in the tenthousand samples. Moreover, in the case where the first preferredembodiment and a second comparison example in which the whole dicingline was covered by the support layer 20 in the first preferredembodiment were compared with regard to a time interval at which thedressing process for a dicing saw was carried out, the dressing processfor the dicing saw was needed to be carried out every five dicing linesin the first preferred embodiment, while in the second comparisonexample, the dressing process was needed to be carried out every singledicing line. Note that cutting a motherboard with a clogged dicing sawmay cause a problem that the motherboard is broken, cracked, or thelike.

The support layer 20 is not positioned on the dicing line L aside fromthe intersecting portion 21 a. With this, clogging is unlikely to begenerated in a dicing saw that is used for dicing the multilayer body 35in comparison with a case in which a resin layer is provided on theoverall dicing line L, or the like, for example.

As discussed thus far, the retaining member 21 being formed so as tointersect with the line main body 12 a of the connection line 12 in thepresent preferred embodiment, the support layer 20 is disposed separatefrom an end side of the piezoelectric substrate 40, and there areprovided the support layer main body 20 that encloses the functionalelement unit 11 and the retaining member 21 that is not connected to thesupport layer 20 and extends to the end side of the piezoelectricsubstrate 40 in the elastic wave device 1.

In order to more effectively significantly reduce, minimize or preventthe separation of the connection line 12, it is preferable for theplurality of intersecting portions 21 a to be provided at set intervalson each side of each region of the multilayer body 35 configuring theelastic wave device 1.

Further, as shown in FIGS. 10 and 11, it is preferable to provide thesupport layer 20 so that the intersecting portion 21 a covers an endportion of the connection unit 12 b on a line main body 12 a side.Furthermore, as shown in FIG. 14, the retaining member 21 is notconnected to the support layer 20 and covers a portion of the electrodeunit 41, and another portion of the electrode unit 41 may be exposedfrom the retaining member 21.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. A method for manufacturing an elastic wave devicecomprising: a step of forming a plurality of functional element unitsand a connection line that electrically connects the plurality offunctional element units on one principal surface of a motherboardhaving piezoelectricity; a step of forming a support layer made of resinthat encloses the functional element units on the one principal surfaceof the motherboard; and a step of obtaining an elastic wave devicehaving the functional element unit by dividing a multilayer bodyincluding the motherboard, the functional element units, and the supportlayer into a plurality of sections along a dicing line; wherein theconnection line includes a line main body positioned on the dicing line,and a connection unit in which the line main body and the functionalelement units are electrically connected; and the method furtherincluding a step of forming a retaining member made of resin whichstraddles the line main body in a width direction of the line main bodyand is separate from the support layer on the motherboard prior todividing the multilayer body.
 2. The method for manufacturing an elasticwave device according to claim 1, wherein the retaining member is formedto cover an end portion of the connection unit on a line main body side.3. The method for manufacturing an elastic wave device according toclaim 1, wherein the retaining member is formed so that an area wherethe retaining member is not provided is larger than an area where theretaining member is provided in a region in which the dicing line ispositioned.
 4. The method for manufacturing an elastic wave deviceaccording to claim 1, wherein the retaining member and the support layerare formed in a same step or a same technical process.
 5. The method formanufacturing an elastic wave device according to claim 1, wherein theelastic wave device is one of a surface acoustic wave device and aboundary wave device.
 6. The method for manufacturing an elastic wavedevice according to claim 1, wherein the plurality of functional elementunits are formed in a matrix configuration on the motherboard.
 7. Themethod for manufacturing an elastic wave device according to claim 1,wherein the retaining member includes an intersecting portion that isnot connected to the support layer and intersects with the line mainbody.
 8. The method for manufacturing an elastic wave device accordingto claim 7, wherein only the intersecting portion of the retainingmember is formed on the line main body and a portion of the retainingmember other than the intersecting portion is not provided on the linemain body.
 9. The method for manufacturing an elastic wave deviceaccording to claim 1, further comprising the step of providing a coverto be supported by the support layer and to cover the functional elementunit.
 10. The method for manufacturing an elastic wave device accordingto claim 9, further comprising the step of forming via holes in thecover and the support layer.
 11. The method for manufacturing an elasticwave device according to claim 1, wherein an area where the retainingmember is not disposed is larger than an area where the retaining memberis disposed on the dicing line.
 12. The method for manufacturing anelastic wave device according to claim 1, wherein the retaining memberincludes a plurality of intersecting portions not connected to thesupport layer and intersecting with the line main body, the plurality ofintersecting portions being arranged at set intervals on side of eachregion of the multilayer body.
 13. An elastic wave device comprising: apiezoelectric substrate; a functional element unit that is provided onone principal surface of the piezoelectric substrate; an electrode unitthat is electrically connected to the functional element unit andextends to an end side of the piezoelectric substrate; a support layerthat is provided on the one principal surface of the piezoelectricsubstrate and encloses the functional element unit; and a cover that issupported by the support layer and covers the functional element unit;wherein the support layer is separate from the end side of thepiezoelectric substrate and encloses the functional element unit; andthe device further comprises a retaining member made of resin that isseparate from the support layer on the piezoelectric substrate andextends to the end side of the piezoelectric substrate.
 14. The elasticwave device according to claim 13, wherein the retaining member coversan end portion of the connection unit on a line main body side.
 15. Theelastic wave device according to claim 13, wherein the retaining memberis configured such that an area where the retaining member is notprovided is larger than an area where the retaining member is providedin a region in which the dicing line is positioned.
 16. The elastic wavedevice according to claim 13, wherein the retaining member and thesupport layer are made of a same material.
 17. The elastic wave deviceaccording to claim 13, wherein the elastic wave device is one of asurface acoustic wave device and a boundary wave device.
 18. The elasticwave device according to claim 13, wherein the plurality of functionalelement units are arranged in a matrix configuration on the motherboard.19. The elastic wave device according to claim 18, wherein the retainingmember includes an intersecting portion that is not connected to thesupport layer and intersects with the line main body.
 20. The elasticwave device according to claim 19, wherein only the intersecting portionof the retaining member is provided on the line main body and a portionof the retaining member other than the intersecting portion is notprovided on the line main body.